Treating those two problems may help improve sleep for menopausal women, the new study findings suggest.

"Poor sleep is one of the major issues that menopausal women seek treatment for from their doctors," said study co-author Megan Mahoney. She is a professor of comparative biosciences at the University of Illinois at Urbana-Champaign.

Sleep disruptions are "a huge health care burden, and it's a huge burden on the women's quality of life. Investigating what's underlying this is very important," Mahoney said in a university news release.

For the study, the researchers analyzed data from 776 women, aged 45 to 54, in the Baltimore area. Following them for up to seven years, the investigators found that hot flashes and depression were strongly associated with poor sleep across all stages of menopause.

According to study co-author Rebecca Smith, "It indicates that when dealing with sleep problems, physicians should be asking about other symptoms related to menopause, especially looking for signs of depression and asking about hot flashes." Smith is a professor of pathobiology at the university.

"Sleep disturbances in menopause are part of a bigger picture that physicians should be looking at," she added.

Some hopeful news also emerged from the study: Many women with restless sleep and insomnia during menopause did not have sleep problems before or after menopause.

"That's a hopeful thing for women who feel like their sleep has gone downhill since they hit the menopause transition: It might not be bad forever," Smith said. "Your sleep does change, but the change may not be permanent."